Talvivaara Mining Co., the Finnish nickel miner, plunged to a record in London trading after another wastewater leak was detected at its only mining site.

Talvivaara dropped 18 percent to 13.50 pence at 10:19 a.m. in London, the lowest since it first sold shares to the public in May 2007. Trading volume exceeded 3.6 million shares, almost three times the three-month daily average.

The company detected a leak yesterday at the gypsum pond of its Sotkamo mine in eastern Finland, according to a statement today. Safety capacity is “sufficient” to manage the leak, it said.

“This string of problems must end,” Jari Raeisaenen, an analyst at Pohjola Bank Oyj, said by phone from Helsinki. “In about a year a turnaround in production would need to be visible to prevent financial troubles recurring.”

The latest events add to the plight of the troubled miner, which cut its production forecast three times last year to about 13,000 metric tons from an initial estimate of as much as 30,000 tons. Excess water at its open-pit mine site, an 11-day leak of waste water in November and low nickel prices have hurt the Espoo, Finland-based mine owner.

The company said today it will increase purified water discharge to regain water capacity in advance of the spring melt. About 250,000 cubic meters of water have leaked from the pond section adjacent to where the previous leak happened in November.

Last month, Talvivaara shareholders approved a 261 million-euro rights ($340 million) offer to help the company stave off default and bankruptcy.

“Getting production on track is the most pressing issue, that’s the way to get cash flow positive and ultimately generate profit,” Raeisaenen said.